JPH0145476B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to the general formula (): R _3-o PXn () [wherein: R has 1 to 18 carbon atoms, preferably 1 to
8 straight-chain and/or branched alkyl-, cycloalkyl-, aryl-, alkylaryl- and aralkyl groups, or groups -OR' or -SR' (wherein
R' represents aryl or alkyl having 1 to 8 carbon atoms), or a group

[Formula] (where R'' represents an alkyl group having 2 to 8 carbon atoms),
X represents a halogen atom, especially a chlorine atom, a bromine atom or an iodine atom, and n is 0, 1, 2 or 3]
The general formula (): R _3-o P(O)Xn () [In the formula: R, X and n represent the above]
The present invention relates to a method for producing a compound of. Compounds of the general formula are combined with oxidizing agents such as O ₂ , NO,
Oxidation with NO ₂ , SO ₂ , SO ₂ Cl ₂ , SO ₃ is known (Houben Weyl, Methoden der Organischen Chemie, Vol. 12/
Volumes 1 and 12/2 and Kosolapoff/Maier, Organic Phosphorus Campauns.
Compounds), Wiley-Interscience (1972). However, these known methods have a number of drawbacks. Most conventionally used oxidizing agents are gases, and therefore oxidation is not possible with gas.
Must be carried out as a liquid reaction. In order to achieve high reaction rates, it is then necessary to use large amounts of gas within a short time or to work at elevated pressures. It is technically complex and requires expensive equipment. Particularly if the compound of the formula is easily volatile, there is an inter alia risk of explosion in the gas chamber if an excessive amount of the same is entrained in the gas chamber during the reaction. In order to avoid even greater yield losses, it is necessary to use an efficient waste gas cooler to prevent the entrainment of volatile compounds of the formula or formula. Also, the oxidizing agents mentioned often cannot be used for all the compounds of the formula, but only for the oxidation of a small number of each of these compounds. That is, EP-A-O010368 states that phenyldichlorophosphane is brought to atmospheric pressure by 2C ₆ H ₅ PCl ₂ +O ₂ about 30-60℃ ---→ 2C ₆ H ₅ P(O)Cl ₂ describes a method of oxidizing with oxygen to produce phenylphosphonic acid dichloride. When the same reaction is applied to CH ₃ PCl ₂ , significant yield losses occur due to the expulsion of CH ₃ PCl ₂ . Furthermore, long reaction times are required for reaction completion. (Hoben Weyl, Vol. 12/1, p. 398: 86% yield after 24 hours of reaction). Furthermore, when the same reaction experiment was attempted, sudden combustion was often observed. During the oxidation of CH ₃ PBr ₂ with NO ₂ (L. Maier, Helv. Chem. Acta 1963, Vol. 46, p. 2667),
A significant decrease in yield was observed due to PC splitting (yield: 70% of the theoretical value). C ₆ H ₅ PCl ₂ +
SO ₂ Cl ₂ →C ₆ H ₅ P(O)Cl ₂ + SOCl ₂ When the oxidation is carried out using SO ₂ Cl ₂ thionyl chloride is formed, which is separated from the desired long end product by distillation. Must (VA Petrov)
etc., Chemical Abstracts (Chem.Abs.)
(1962, Vol. 57, p. 5583). Reactions using SO ₃ are technically difficult and expensive. Yet another known method for oxidizing compounds of the formula: a RPCl ₂ chlorination ---→ RPCl ₄ b RPCl ₄ H ₂ O ---→ RPOCl ₂ +2HCl or SO ₂ ---→ RPOCl ₂ +SOCl ₂ chlorination and subsequent hydrolysis (Hoben Weyl, Methoden der organischen Chemie).
Chemie) Vol. 12/1, p. 390). This method is tedious and requires at least two steps. The following formula: 3C ₆ H ₅ PCl ₂ +SO ₂ →2C ₆ H ₅ P(O)Cl ₂ +C ₆ H ₅ P
Oxidation using SO ₂ with (S)Cl ₂ yields mixture products (E. Fluck, H. Binder, Angew.
Chemie (1965, Vol. 77, p. 381) and requires an extremely long reaction time (42 days). Furthermore, a method of oxidizing PCl ₃ with oxygen in the presence of a hydrocarbon is also known (Hoben Weyl, 12th/
Volume 1, page 399). R-H+ _2PCl3 + _O2 →RP(O) _Cl2 + _POCl3 +HCl This method gives a yield of only 18-45% of the theoretical value. The object of the invention is to overcome the drawbacks of the known methods. However, it was unexpectedly discovered that this problem could be solved in an extremely simple way by using chlorosulfonic acid as an oxidizing agent and carrying out the reaction in a homogeneous liquid phase, optionally in the presence of a solvent. Ta. The reaction is preferably carried out at temperatures between -30 and 150°C. The reaction components are used in a molar ratio of chlorosulfonic acid:organophosphorus compound according to the formula 1:1 to 1:1.1. The products of the general formula obtained by the process of the invention are valuable intermediates for the production of plant protection agents, flame retardants or synthetic resin additives. The starting materials according to the formula are known compounds and can be prepared by generally known methods of phosphorus organic chemistry. The method according to the invention has many advantages over known methods. The reaction takes place in each case in a homogeneous liquid phase,
Therefore, high reaction rates can be achieved. The yield of the reaction is quantitative in most cases and the reaction products are produced in highly pure form. In many cases purification steps such as distillation are unnecessary. In order to obtain highly pure products with surprisingly low sulfur contents, short stripping in vacuo is often sufficient. When carrying out the process, the component to be oxidized of the formula can be placed in a reactor and the chlorosulfonic acid can be added thereto, or vice versa. It is optionally advantageous to introduce both components simultaneously, optionally in addition to the final product being present, into the reactor. The reaction begins immediately when the required temperature is reached.
This proceeds exothermically, always with gas evolution, and the desired product of the general formula remains. If the components of the formula are volatile, it is advantageous to add the oxidizing agent chlorosulfonic acid into the gas outlet in order to minimize yield losses due to entrainment of low temperature volatile starting materials. In some cases, a washing column may be provided in the gas outlet path, in which the accompanying components are brought into contact with an oxidizing agent and reacted with HCl and
A method of washing out SO ₂ from waste gas is recommended. The reaction can be carried out without a solvent, but it can also be carried out in the presence of an inert solvent. The method of the invention is illustrated in detail by the following examples. Example 1 331 g (2.83 mol) of methyldichlorophosphane and 327 g (2.82 mol) of chlorosulfonic acid are placed under cooling in a 1-necked flask equipped with a stirrer, an internal thermometer, a reflux condenser and two addition funnels. Drop them at the same time and let them react. In this case, the chlorosulfonic acid is introduced through a reflux condenser, and the waste gas exits through the same reflux condenser. The reaction temperature is maintained at about 25-30°C by cooling. After a dropwise addition time of 1 hour, stirring is continued for 1 hour at room temperature. The crude product is subsequently stripped at 32° C. and 0.5 mbar. Methanephosphonic acid dichloride
371 g (99% of theory) were obtained, which was determined by gas chromatography to contain 99.4% of the compound. The product crystallizes on standing overnight (melting point 32°C). The residual amount of sulfur is 0.4%. Example 2 58.25 g (0.5 mol) of chlorosulfonic acid are placed in a 1-necked flask equipped with an internal thermometer, addition funnel, stirrer and reflux condenser. Add 58.5 g (0.5 mol) of dimethyldichlorophosphane to 20°C while cooling with water.
Add dropwise within 30 minutes with vigorous stirring at an internal temperature of . Then add 699 more chlorsulfonic acid.
g (6 mol) was added thereto, and 702 g (6 mol) of methyldichlorophosphane was similarly added thereto dropwise in the same manner as above for 4 hours. After reacting for 1 hour, 32℃
and stripping at 130m bar.
820 g (95% of theory) of methanephosphonic acid dichloride are obtained (content of the same compound 99.1% as determined by gas chromatography). The product crystallizes on standing overnight (melting point 30°C). Example 3 1228 g (1.05 mol) of methyldichlorophosphane and chlorosulfonic acid in a two-necked flask equipped with a stirrer, an internal thermometer, a dropping funnel and a 15 cm Raschitz column with an intensive condenser and dropping funnel and a cooling bath. 1165 g (10.0 mol) was added dropwise at the same time. Addition of chlorosulfonic acid is carried out using a reflux condenser and
15cm - It is done through a Ratshitshi Kalam. Cooling keeps the internal temperature below 30°C. Addition time is 3 hours. After reaction for 1 hour, stripping is carried out for 30 minutes at 130 mbar/35°C.
1324 g (99.6% of theory) of methanephosphonic acid dichloride (content of the same compound 99.4% determined by gas chromatography) remain, which gradually crystallizes completely (melting point 31° C.). The residual amount of sulfur is 0.03%. Example 4 49.5 g (0.42 mol) of chlorsulfonic acid and 100 g of dichloromethane in a 250 ml multi-necked flask equipped with a stirrer, an internal thermometer, a reflux condenser and an addition funnel.
Introduce 41 ml of dimethylchlorophosphane into it
g (0.42 mol) dropwise over 30 minutes. The cooling temperature is maintained at 15-20°C by cooling. After-stir for 2 hours at room temperature. The solvent is then removed at 130 mbar and 80°C. 45 g (95% of theory) of dimethylphosphinic acid chloride (content 97..8% as determined by gas chromatography) remain. Example 5 In an apparatus similar to that described in Example 4, chlorosulfonic acid was added.
46.4 g (0.4 mol) are introduced and reacted with 54 g (0.41 mol) of ethyldichlorophosphane at 20-30°C. Addition time is 80 minutes. After 30 minutes of post-reaction, stripping is carried out at 130 mbar/30°C. 57 g (97% of theory) of ethanephosphonic acid dichloride are obtained. ³¹ P—NMR (Nuclear Magnetic Resonance)—No impurities observed in the spectrum. Example 6 Into the same apparatus as in Example 4, 35.8 g (0.2 mol) of phenyldichlorophosphane was introduced, and while cooling to 25-30°C, 23.4 g (0.2 mol) of chlorosulfonic acid was introduced.
react with. Addition time is 30 minutes. After 1 hour's reaction, strip at 33A bar/35°C. Phenylphosphonic acid dichloride 39g (0.2
Mol, content 98.2 as determined by gas chromatography
%) remains. Example 7 In an apparatus similar to Example 4, 116.5% of chlorsulfonic acid was added.
g (1 mol) and preheated to 50°C. 137.5 g of phosphorus trichloride are then added dropwise over an addition time of 1.5 hours. In that case, the reaction temperature is maintained at about 30°C by cooling after the reaction starts at about 50°C. This is followed by refluxing and distillation for 30 minutes at a top temperature of up to 74°C. 130 g of crude phosphorus chloride oxide (content 85% as determined by gas chromatography) are obtained. Example 8 0.2 mol of phosphorus tribromide is introduced into the apparatus described in Example 4 and reacted with 0.2 mol of chlorosulfonic acid at a reaction temperature of 45 DEG to 47 DEG C. After an addition time of 30 minutes and after-reaction of 30 minutes, the product begins to crystallize at about 35°C. Stripping at 130 mbar/35°C. 50 g of crude phosphorous bromide oxide (melting point 48 DEG C.) remain, which according to ^{the 31} P-NMR spectrum contains 75% P as P(O)Br ₃ . Example 9 S-propylthiophosphite dichloride (0.45 mol) was introduced into the above apparatus in advance, and 18 to 20
52.6 g of chlorsulfonic acid (0.45
mol). Addition time is 30 minutes. 30
After a post-reaction of minutes, stripping is carried out at 100 mbar/30°C. 86 g of crude product remained, which according to the ³¹ P-NMR spectrum contained 73% P as S-propylthiophosphate dichloride.
contains. Example 10 In a device similar to Example 4, 23.3 g of chlorsulfonic acid
(0.2 mol) was introduced in advance, and 62 g (0.2 mol) of triphenyl phosphite was added dropwise for 1 hour while cooling. about 20
After a reaction time of minutes, the reaction mixture becomes viscous, so about 20 ml of dichloromethane are added as solvent. The reaction temperature is kept at 25-30°C. After 1 hour's reaction, strip at 100 m/bar/35°C. 70 g of crude product was obtained, which is ³¹ P-
According to the NMR spectrum, it contains 65% P as triphenyl phosphate. Example 11 In an apparatus similar to Example 4, 116.5% of chlorsulfonic acid was added.
208 g (1 mol) of tributylphosphane and 60
Allow to react within minutes. By stopping cooling near the end of the addition, the reaction temperature increases to 34°C. A strongly exothermic reaction occurs during stripping (0.5 mbar/70°C). The temperature rises to 140℃. Then strip again at 1 mbar/80°C. 263g of tributylphosphine oxide remained as an HCl-adduct, and elemental analysis and ^31P -NMR-
Spectrum of tributylphosphine oxide
The presence of 90% of P as HCl adduct is established. Example 12 23.3 g (0.2 mol) of chlorosulfonic acid in 40 ml of dichloromethane are introduced into the standard apparatus (Example 4) and then, with stirring, tri-n-octylphosphine is introduced.
72 g (0.2 mol) are added dropwise over 45 minutes. Maintain the temperature below 30℃ by gentle cooling. After a post-reaction time of 1 hour, it is stripped at 95° C./1.3 mbar.
77 g of crude product are obtained, which according to the ³¹ P-NMR spectrum contains 91% of P as oxidized tri-n-octylphosphine-HCl adduct. Example 13 0.75 mol of chlorsulfonic acid was introduced into the standard apparatus (Example 4), and 0.75 mol of 2-chloro-1,3,2-dioxaphosphorane was added dropwise for 35 minutes while cooling to 22-28°C. do. 65℃/after 45 minutes post-reaction
Stripping at 30m bar. 109 g of pale yellow crude product was obtained, which was determined by ³¹ P-NMR-
The spectrum shows 2-chloro-2-oxo-1,
Contains 75% P as 3,2-dioxaphosphorane.

Claims (1)

[Claims] 1 General formula (): R _3-o PXn () [In the formula: R is a straight chain and/or branched alkyl having 1 to 18 carbon atoms, cycloalkyl, aryl, represents an alkylaryl or aralkyl group, or a group -OR' or -SR' (where R' represents an alkyl or aryl group having 1 to 8 carbon atoms), or a group [formula] (where R "represents an alkyl group having 2 to 8 carbon atoms), X represents a halogen atom, and n is 0, 1, 2 or 3", an organic phosphorus compound of the general formula (): R _{3- o} P(O)Xn () [In the formula: R, X and n represent the above]
A method for oxidizing an organic phosphorus compound, characterized in that chlorosulfonic acid is used as an oxidizing agent and the reaction is carried out in a homogeneous liquid phase. 2. The method according to claim 1, wherein the oxidation is carried out at a temperature of -30 to 150°C. 3. The method according to claim 1 or 2, wherein the reaction components chlorosulfonic acid and the organic phosphorus compound are used in a molar ratio of 1:1 to 1:1.1.